Firearms require skill and consistency of use in order to accurately aim and discharge the weapon at an intended target. In order to aim a firearm, the user typically lines up the aiming sight of the firearm with a target in the user's field of vision. The aiming sight of most firearms includes a bead or other protrusion at the end of the firearm barrel, and an open sight or rib disposed on the barrel closer to the user. The user typically places the user's chin into contact with the firearm stock while tightly holding the firearm stock against the user's shoulder. The user then lines up the open sight or rib, the bead, and the target in the field of vision of the user as the user looks down the barrel of the firearm.
Traditional firearms such as rifles, shotguns, and pistols are typically not made to fit the varying physical attributes of an individual user. In particular, the length of a firearm user's arms and neck, as well as the distance between a firearm user's chin and eye, can impact whether a firearm fits the user. As a result, it may be difficult for some users to properly align their head and eye positions such that the user's field of vision is straight down the barrel and through the aiming sight in a manner that results in precise aiming of the firearm. Without achieving head and eye positions that are level to the firearm barrel, the firearm user's vision may be skewed, making it difficult to take accurate aim.
Firearms can be modified to provide the proper fit for a user according to a user's unique physical attributes. Modifications of this nature are often performed by a gunsmith or firearm vendor and can add an unanticipated expense after the purchase of the firearm. Moreover, the ability to determine the proper fit for a firearm user typically remains an inexact science, usually relying on trial and error of firearm modification. Therefore, a need exists for an accurate method and apparatus that allows a firearm user to determine the manner and amount of firearm modification necessary to promote the proper head and eye positions for accurate aiming of the firearm.